Typical welding blankets of the prior art are made of carbon-based fibers formed into needle-punched non-woven fabrics. For example, a needle punched carbon fiber welding blanket is described in U.S. Pat. No. 6,696,374 issued to Bridgeman, et al, which is incorporated herein, by reference, in its entirety. Other related prior art patents include U.S. Pat. Nos. 3,916,057, 4,332,600, 4,332,601, 4,500,593, 4,508,777, 4,849,273, 5,582,912, 6,383,623, 6,551,951, and 6,579,396. Each of these related prior art patents is incorporated herein, in its entirety, by reference.
The present invention provides economic, yet effective and drapeable/flexible alternatives to single layer sheet materials of the prior art, including needle punched nonwovens and single layer woven and knitted carbon-based fiber fabrics of the prior art. The sheet materials of the present invention are either woven or knitted materials and their layers may be unified together during the weaving or knitting process or, alternatively, may be stitched together in a separate/subsequent, post weaving or knitting process/step.